I completed this one (after several goes) by making sure I had my pet with me (if you don't have a pet you could maybe get a ten minute trial one to help you) and I made sure I ate some royal stew. I did notice thought that when I ate the stew I was unable to pick up the speed boosts things on the way round. Another thing I noticed is that when I accepted the goal it changed me automatically from a ninja to an adventurer (which seemed strange as it's in the ninja quest line).